Methods for the synthesis of large numbers of diverse compounds which can be screened for various possible physiological or other activities are of interest (Ellman, et. al. Chem. Rev. 96: 555-600 (1996)). Techniques have been developed in which individual units are added sequentially as part of the chemical synthesis to produce all or a substantial number of the possible compounds which can result from all the different choices possible at each sequential stage of the synthesis. For these techniques to be successful, it is necessary for the compounds to be amenable to methods by which one can determine the structure of the compounds so made. Examples of such techniques include, the technique of Brenner and Lerner (PNAS USA 81: 5381-83 (1992)) and WO 93/20242, according to which oligonucleotides are produced in parallel with oligopeptides; the oligonucleotides function as genetic tags and are chemically linked to the oligopeptides, which are the compounds of interest. WO 93/06121 teaches methods for particles-based synthesis of random oligomers wherein identification tags on the particles are used to facilitate identification of the oligomer sequence synthesized. Ohlmeyer et al., (Proc. Natl. Acad. Sci. USA, 90, 10922-10926, 1993) discloses a detachable tagging system.